XVI International Botanical Congess

Degraded and fragmented forests can be restored by accelerating the natural process of forest succession (accelerated natural regeneration or ANR). A two-year project in northern Thailand studied abandoned agricultural clearings in montane forest to identify barriers to the succession process, so that ANR techniques could be devised to overcome the limiting factors. Fruit production, seed dispersal, seed germination and seedling survival and growth of tree species were monitored and experiments were carried out to determine the effect of factors such as weed competition, light and moisture on germination and seedling establishment. Results are presented for contrasting species to show how their colonisation of degraded areas is blocked at different stages of the life-cycle and the factors limiting each example are identified. Species traits associated with each regeneration pattern are discussed.